The present invention relates to a fixing device, and more particularly relates to a fixing device of electromagnetic induction heating method. This kind of fixing device is used, for example, as a component of an image forming apparatus such as electrophotographic copiers, printers and facsimiles.
As fixing devices of this kind, as shown in JP 3426229 C, JP 3519401 C and JP 2000-181258 A, there has been known a fixing device having a fixing roller and a pressure roller which are in pressure contact with each other in such a way as to form a nip section for heating a magnetic material layer (such as alloy layers of iron, chrome and nickel; hereinbelow referred to as “heat generating layer”) of the fixing roller by electromagnetic induction, transporting recording paper with a toner image attached thereto through the nip section, and melting and fixing the toner image on the recording paper by heat generation in the fixing roller. In order to enhance a temperature rise characteristic by reducing thermal capacity, the heat generating layer of the fixing roller is set to have a thickness as small as, for example, about 100 μm.